From 749262693247808e2db5a2eb29a11ad3cfec211c Mon Sep 17 00:00:00 2001 From: Anton Khirnov Date: Mon, 18 Jul 2016 00:04:16 +0200 Subject: [PATCH] pthread_frame: use atomics for PerThreadContext.state Merges Libav commit 64a31b28. Signed-off-by: wm4 --- libavcodec/pthread_frame.c | 84 +++++++++++++++++++++----------------- 1 file changed, 47 insertions(+), 37 deletions(-) diff --git a/libavcodec/pthread_frame.c b/libavcodec/pthread_frame.c index 272587f53c..bd250002a3 100644 --- a/libavcodec/pthread_frame.c +++ b/libavcodec/pthread_frame.c @@ -24,6 +24,7 @@ #include "config.h" +#include #include #include "avcodec.h" @@ -43,6 +44,25 @@ #include "libavutil/opt.h" #include "libavutil/thread.h" +enum { + ///< Set when the thread is awaiting a packet. + STATE_INPUT_READY, + ///< Set before the codec has called ff_thread_finish_setup(). + STATE_SETTING_UP, + /** + * Set when the codec calls get_buffer(). + * State is returned to STATE_SETTING_UP afterwards. + */ + STATE_GET_BUFFER, + /** + * Set when the codec calls get_format(). + * State is returned to STATE_SETTING_UP afterwards. + */ + STATE_GET_FORMAT, + ///< Set after the codec has called ff_thread_finish_setup(). + STATE_SETUP_FINISHED, +}; + /** * Context used by codec threads and stored in their AVCodecInternal thread_ctx. */ @@ -66,19 +86,7 @@ typedef struct PerThreadContext { int got_frame; ///< The output of got_picture_ptr from the last avcodec_decode_video() call. int result; ///< The result of the last codec decode/encode() call. - enum { - STATE_INPUT_READY, ///< Set when the thread is awaiting a packet. - STATE_SETTING_UP, ///< Set before the codec has called ff_thread_finish_setup(). - STATE_GET_BUFFER, /**< - * Set when the codec calls get_buffer(). - * State is returned to STATE_SETTING_UP afterwards. - */ - STATE_GET_FORMAT, /**< - * Set when the codec calls get_format(). - * State is returned to STATE_SETTING_UP afterwards. - */ - STATE_SETUP_FINISHED ///< Set after the codec has called ff_thread_finish_setup(). - } state; + atomic_int state; /** * Array of frames passed to ff_thread_release_buffer(). @@ -133,8 +141,8 @@ static attribute_align_arg void *frame_worker_thread(void *arg) pthread_mutex_lock(&p->mutex); while (1) { - while (p->state == STATE_INPUT_READY && !p->die) - pthread_cond_wait(&p->input_cond, &p->mutex); + while (atomic_load(&p->state) == STATE_INPUT_READY && !p->die) + pthread_cond_wait(&p->input_cond, &p->mutex); if (p->die) break; @@ -152,7 +160,8 @@ static attribute_align_arg void *frame_worker_thread(void *arg) av_frame_unref(p->frame); } - if (p->state == STATE_SETTING_UP) ff_thread_finish_setup(avctx); + if (atomic_load(&p->state) == STATE_SETTING_UP) + ff_thread_finish_setup(avctx); pthread_mutex_lock(&p->progress_mutex); #if 0 //BUFREF-FIXME @@ -162,7 +171,7 @@ static attribute_align_arg void *frame_worker_thread(void *arg) p->progress[i][1] = INT_MAX; } #endif - p->state = STATE_INPUT_READY; + atomic_store(&p->state, STATE_INPUT_READY); pthread_cond_broadcast(&p->progress_cond); pthread_cond_signal(&p->output_cond); @@ -323,9 +332,9 @@ static int submit_packet(PerThreadContext *p, AVPacket *avpkt) if (prev_thread) { int err; - if (prev_thread->state == STATE_SETTING_UP) { + if (atomic_load(&prev_thread->state) == STATE_SETTING_UP) { pthread_mutex_lock(&prev_thread->progress_mutex); - while (prev_thread->state == STATE_SETTING_UP) + while (atomic_load(&prev_thread->state) == STATE_SETTING_UP) pthread_cond_wait(&prev_thread->progress_cond, &prev_thread->progress_mutex); pthread_mutex_unlock(&prev_thread->progress_mutex); } @@ -345,7 +354,7 @@ static int submit_packet(PerThreadContext *p, AVPacket *avpkt) return ret; } - p->state = STATE_SETTING_UP; + atomic_store(&p->state, STATE_SETTING_UP); pthread_cond_signal(&p->input_cond); pthread_mutex_unlock(&p->mutex); @@ -358,13 +367,13 @@ static int submit_packet(PerThreadContext *p, AVPacket *avpkt) if (!p->avctx->thread_safe_callbacks && ( p->avctx->get_format != avcodec_default_get_format || p->avctx->get_buffer2 != avcodec_default_get_buffer2)) { - while (p->state != STATE_SETUP_FINISHED && p->state != STATE_INPUT_READY) { + while (atomic_load(&p->state) != STATE_SETUP_FINISHED && atomic_load(&p->state) != STATE_INPUT_READY) { int call_done = 1; pthread_mutex_lock(&p->progress_mutex); - while (p->state == STATE_SETTING_UP) + while (atomic_load(&p->state) == STATE_SETTING_UP) pthread_cond_wait(&p->progress_cond, &p->progress_mutex); - switch (p->state) { + switch (atomic_load_explicit(&p->state, memory_order_acquire)) { case STATE_GET_BUFFER: p->result = ff_get_buffer(p->avctx, p->requested_frame, p->requested_flags); break; @@ -376,7 +385,7 @@ static int submit_packet(PerThreadContext *p, AVPacket *avpkt) break; } if (call_done) { - p->state = STATE_SETTING_UP; + atomic_store(&p->state, STATE_SETTING_UP); pthread_cond_signal(&p->progress_cond); } pthread_mutex_unlock(&p->progress_mutex); @@ -431,9 +440,9 @@ int ff_thread_decode_frame(AVCodecContext *avctx, do { p = &fctx->threads[finished++]; - if (p->state != STATE_INPUT_READY) { + if (atomic_load(&p->state) != STATE_INPUT_READY) { pthread_mutex_lock(&p->progress_mutex); - while (p->state != STATE_INPUT_READY) + while (atomic_load_explicit(&p->state, memory_order_relaxed) != STATE_INPUT_READY) pthread_cond_wait(&p->output_cond, &p->progress_mutex); pthread_mutex_unlock(&p->progress_mutex); } @@ -516,11 +525,12 @@ void ff_thread_finish_setup(AVCodecContext *avctx) { if (!(avctx->active_thread_type&FF_THREAD_FRAME)) return; pthread_mutex_lock(&p->progress_mutex); - if(p->state == STATE_SETUP_FINISHED){ + if(atomic_load(&p->state) == STATE_SETUP_FINISHED){ av_log(avctx, AV_LOG_WARNING, "Multiple ff_thread_finish_setup() calls\n"); } - p->state = STATE_SETUP_FINISHED; + atomic_store(&p->state, STATE_SETUP_FINISHED); + pthread_cond_broadcast(&p->progress_cond); pthread_mutex_unlock(&p->progress_mutex); } @@ -533,9 +543,9 @@ static void park_frame_worker_threads(FrameThreadContext *fctx, int thread_count for (i = 0; i < thread_count; i++) { PerThreadContext *p = &fctx->threads[i]; - if (p->state != STATE_INPUT_READY) { + if (atomic_load(&p->state) != STATE_INPUT_READY) { pthread_mutex_lock(&p->progress_mutex); - while (p->state != STATE_INPUT_READY) + while (atomic_load(&p->state) != STATE_INPUT_READY) pthread_cond_wait(&p->output_cond, &p->progress_mutex); pthread_mutex_unlock(&p->progress_mutex); } @@ -753,7 +763,7 @@ void ff_thread_flush(AVCodecContext *avctx) int ff_thread_can_start_frame(AVCodecContext *avctx) { PerThreadContext *p = avctx->internal->thread_ctx; - if ((avctx->active_thread_type&FF_THREAD_FRAME) && p->state != STATE_SETTING_UP && + if ((avctx->active_thread_type&FF_THREAD_FRAME) && atomic_load(&p->state) != STATE_SETTING_UP && (avctx->codec->update_thread_context || !THREAD_SAFE_CALLBACKS(avctx))) { return 0; } @@ -772,7 +782,7 @@ static int thread_get_buffer_internal(AVCodecContext *avctx, ThreadFrame *f, int if (!(avctx->active_thread_type & FF_THREAD_FRAME)) return ff_get_buffer(avctx, f->f, flags); - if (p->state != STATE_SETTING_UP && + if (atomic_load(&p->state) != STATE_SETTING_UP && (avctx->codec->update_thread_context || !THREAD_SAFE_CALLBACKS(avctx))) { av_log(avctx, AV_LOG_ERROR, "get_buffer() cannot be called after ff_thread_finish_setup()\n"); return -1; @@ -797,10 +807,10 @@ static int thread_get_buffer_internal(AVCodecContext *avctx, ThreadFrame *f, int pthread_mutex_lock(&p->progress_mutex); p->requested_frame = f->f; p->requested_flags = flags; - p->state = STATE_GET_BUFFER; + atomic_store_explicit(&p->state, STATE_GET_BUFFER, memory_order_release); pthread_cond_broadcast(&p->progress_cond); - while (p->state != STATE_SETTING_UP) + while (atomic_load(&p->state) != STATE_SETTING_UP) pthread_cond_wait(&p->progress_cond, &p->progress_mutex); err = p->result; @@ -825,16 +835,16 @@ enum AVPixelFormat ff_thread_get_format(AVCodecContext *avctx, const enum AVPixe if (!(avctx->active_thread_type & FF_THREAD_FRAME) || avctx->thread_safe_callbacks || avctx->get_format == avcodec_default_get_format) return ff_get_format(avctx, fmt); - if (p->state != STATE_SETTING_UP) { + if (atomic_load(&p->state) != STATE_SETTING_UP) { av_log(avctx, AV_LOG_ERROR, "get_format() cannot be called after ff_thread_finish_setup()\n"); return -1; } pthread_mutex_lock(&p->progress_mutex); p->available_formats = fmt; - p->state = STATE_GET_FORMAT; + atomic_store(&p->state, STATE_GET_FORMAT); pthread_cond_broadcast(&p->progress_cond); - while (p->state != STATE_SETTING_UP) + while (atomic_load(&p->state) != STATE_SETTING_UP) pthread_cond_wait(&p->progress_cond, &p->progress_mutex); res = p->result_format;